@Article{ 
  AgrBarBos12,
  author = { Agrachev, Andrei and Barilari, Davide and Boscain, Ugo },
  title = { On the Hausdorff volume in sub-Riemannian geometry },
  journal = { Calc. Var. and PDE },
  year = { 2012 },
  volume = { 43 },
  number = { 3-4 },
  pages = { 355-388 },
  URL = { http://cvgmt.sns.it/paper/1788/ },
  note = { cvgmt preprint}
}